Fuel injector



Jan. 5, 1937. Q SCHLAUpn-z- 2,067,131

FUEL INJ ECTOR Filed Aug. 5, 1955 f// AT1-019146,45.

Patented Jan. 5, 1937 FUEL INJECTOR Oswald Schlaupitz, Canton, Ohio, assigner to The Timken Roller Bearing Company,

Canton,

Ohio, a corporation of Ohio Application August 5, 1935, Serial No. 34,701

4 Claims.

A This invention relates to fuel injectors for internal combustion engines of the Diesel type. It hasfor its principal objects to provide the nozzle with a device for filtering the fuel oil passing therethrough, to simplify the operation of forming the discharge orifices and to providev for cheapness of construction and compactness of design. The invention consists in the fuel injector and in the construction, combinations and arrangements of parts hereinafter described and claimed.

In the accompanying drawing, which forms part of this specification and wherein like symbols refer to like parts wherever they occur,

Fig. 1 is a central vertical sectional view of a fuel injector embodying my invention,

Fig. 2 is an end view of the tip or nozzle portion of the injector,

Fig. 3 is a side elevation of a filter sleeve,

Fig. 4 is a section through the nozzle end of an injector provided with a modified arrangement of discharge orifices,

Fig. 5 is an end view of the nozzle or tip shown in Fig. 4,

Fig. 6 is a section similar to Fig. 4, showing another modified construction; and

Fig. '7 is an end view of the nozzle shown in Fig. 6.

'Ihe fuel injector valve or nozzle shown in Figs. 1 and 2 comprises a substantially cylindrical 'casing or main body portion I provided with an axial bore 2 whose lower end opens into a nozzle or tip 3 that is removably secured to said body portion by means of a cap nut Il threaded thereon. The nozzle 3 is a multiple hole nozzle; that is, it is provided at its discharge end with a series of circumferentially spaced discharge orifices 5. The upper end of said bore opens into a cap nut 6 that is threaded into an upstanding boss 1 on the upper end of the body of the injector.- The body portion of the injector has an inlet passageway 8, which communicates with the axial bore near the upper end thereof, and a drain passageway 9 which leads from the interior of the upper cap nut 6.

Located in the bore -2 of the injector is a valve stem or plunger ID in the form of a cylindrical rod whose lower end portion extends into the nozzle 3 and terminates in a fiat end face adapted to bear against the end wall of the nozzle and close with the discharge orifices 5 therein. The plunger I0 extends upwardly into the upper cap nut 6 and is normally'held in closed position 4by means of a helical spring II located in said cap nut between the top thereof and a spring seat I2 supported on the upper end of said plunger. lUpward movementof the plunger is limitedby an adjustable stop in the form of a screw I3 that is threaded through an axial bore provided therefor in the top of the upper cap nut 6 with its inner or lower end disposed in abutting relation to the upper end of the spring seat I2. The stop screw I3 is locked in desired position of adjustment by means of a suitable lock nut I4 threaded on the upper end thereof in abutting relation tothe top of the upper cap nut.

Located ini-the axial bore 2 of the injector is an oil filtering device in the form of a cylindrical member I5, which snugly fits said bore and has an axial Ibore adapted to slidably support the intermediate portion of the spring-loaded valve stem or plunger I0. As shown in Figs. l and 3, the upper portion of this cylindrical filter sleeve I5 is provided opposite the inlet passageway 8 with an exterior annular groove I6 and the portion below said' groove is provided with two series of exterior, longitudinal V-shaped grooves that alternate one with the other. The grooves I'I of one series communicate at their upper series with the annular groove I6 and their lower ends terminate short of the lower` end of the filter sleeve; and the grooves I8 of the other series terminate short of said annular groove and extend clear tothe lower end of said sleeve.

The operation of the device is as follows: Fuel oil enters the inlet passageway 8 of the injector under pressure of the usual fuel injection pump (not shown) and is forced into the exterior annular groove IB of the filter sleeve I5 vand thence into the series of grooves I'I leading downwardly therefrom. From these grooves the oil passes between the peripheral portions of the filter sleeve and axialxbore 2 therefor into the grooves I8 which are open at the lower end of said filter sleeve, the filter action being brought about by the closely fitting portions of said filter sleeve and said bore. The oil is thence forced downwardly around the lower end of the spring-loaded plunger of valve stem Ill; and, when the pressure of the oil overcomes the resistance of the spring II on the plunger, the plunger is raised clear of the discharge orifices 5 in the nozzle 3 and the oil is sprayed from said nozzle through said orifices. Any oil that leaks around the plunger into the upper spring enclosing cap nut 6 is discharged therefrom through the drain passageway 9.

The discharge orifices 5 shown in Figs. 1y and 2 are formed by fitting a longitudinally fluted or grooved plug I9 in a bore 20 provided therefor without departing from the invention and I do in the end of the nozzle cap, the plug and bore being preferably tapered toward the outer end of the nozzle 3 so that the pressure of the oil on said plug tends to seat it firmly in said bore.l In the modified construction shown in Figs. 4 and 5 the discharge oriiices 5a are formed by iiutes or grooves located in lthe bore 20a instead of being located in the plug Ha for said bore. In the pin nozzle construction shown in Figs. 6 and 7, the plunger has a flatsided pin or plug lsb xed to its lower end that ts within a bore Zlib provided therefor in the end of the nozzle, thereby forming a series of circumferentially spaced discharge orifices 5b. It is noted as an important advantage of each of the above arrangements for forming the discharge orifices in the nozzle that it dispenses with the operation of drilling said orifices, which are relatively small and result in considerable drill breakage. Other advantages are that the plug size is such that the hole therefor can be drilled and reamed without drill breakage and that the small grooves or flutes in the hole or plug may be tool cut or breached.

Obviously, numerous changes may be made not wish to be limited to the precise construction shown.

What I claim is:

1. A fuel injector comprising a body portion having a bore therein, an inlet passageway opening into said boreand a discharge orifice leading from said bore, a plunger mounted in .said bore for opening and closing said discharge orice, and a filter mounted in said bore between said inlet passageway and said discharge orice, said iilter comprising a separate member fitting in said bore and provided with a bore adapted to slidably support said plunger.

2. A fuel injector comprising a body portion having an inlet passageway and a series of circumferentially spaced discharge orifices, and a filter mounted in said body portion between said inlet passageway and said discharge orifices, the discharge end of said injector being provided with an axial bore, a plug fitting in said bore,

one of said plug and bore provided with longitudinal grooves that extend substantially straight from end to end thereof to form said discharge orifices, and a plunger slidably supported in said lfilter and having a fiat end face adapted to close the inner ends of said discharge orifices.

3. A fuel injector nozzle comprising a body portion provided at its discharge end with an axial bore, and a plug fitting said bore, one of said plug and bore being provided with longitudinal grooves that extend substantially straight from end to end thereof and form a plurality of circumferentially spaced discharge oriflces and a plunger slidably mounted in said body portion and having a flat end face adapted to close the inner ends of said discharge orifices.

4. A fuel injector comprising a body portion having a bore therein and an inlet passageway opening into said bore near one end thereof, a nozzle member removably secured to said body portion at the other end of said bore and provided with a discharge orice, a sleeve mounted' in said bore and having filtering grooves in its exterior surface, and a valve stem slidably supported in said-sleeve and extending into said nozzle for closing the discharge orice therein.

OSWALD SCHLAUPITZ.

-DI'SOLAIMER 2,067,l31.-0s`wald ,S'hlcupitz, Canton, Ohio. FUEL INJECTOR,

Patent dated January 5, 1937. Disclaimer led June 4, 1937, by the assignee; The Timken ic'ial Gazette June .'29, 1937.]

disclaims the subject matter of claims l and 4 of said Letters Patent.

without departing from the invention and I do in the end of the nozzle cap, the plug and bore being preferably tapered toward the outer end of the nozzle 3 so that the pressure of the oil on said plug tends to seat it firmly in said bore.l In the modified construction shown in Figs. 4 and 5 the discharge oriiices 5a are formed by iiutes or grooves located in lthe bore 20a instead of being located in the plug Ha for said bore. In the pin nozzle construction shown in Figs. 6 and 7, the plunger has a flatsided pin or plug lsb xed to its lower end that ts within a bore Zlib provided therefor in the end of the nozzle, thereby forming a series of circumferentially spaced discharge orifices 5b. It is noted as an important advantage of each of the above arrangements for forming the discharge orifices in the nozzle that it dispenses with the operation of drilling said orifices, which are relatively small and result in considerable drill breakage. Other advantages are that the plug size is such that the hole therefor can be drilled and reamed without drill breakage and that the small grooves or flutes in the hole or plug may be tool cut or breached.

Obviously, numerous changes may be made not wish to be limited to the precise construction shown.

What I claim is:

1. A fuel injector comprising a body portion having a bore therein, an inlet passageway opening into said boreand a discharge orifice leading from said bore, a plunger mounted in .said bore for opening and closing said discharge orice, and a filter mounted in said bore between said inlet passageway and said discharge orice, said iilter comprising a separate member fitting in said bore and provided with a bore adapted to slidably support said plunger.

2. A fuel injector comprising a body portion having an inlet passageway and a series of circumferentially spaced discharge orifices, and a filter mounted in said body portion between said inlet passageway and said discharge orifices, the discharge end of said injector being provided with an axial bore, a plug fitting in said bore,

one of said plug and bore provided with longitudinal grooves that extend substantially straight from end to end thereof to form said discharge orifices, and a plunger slidably supported in said lfilter and having a fiat end face adapted to close the inner ends of said discharge orifices.

3. A fuel injector nozzle comprising a body portion provided at its discharge end with an axial bore, and a plug fitting said bore, one of said plug and bore being provided with longitudinal grooves that extend substantially straight from end to end thereof and form a plurality of circumferentially spaced discharge oriflces and a plunger slidably mounted in said body portion and having a flat end face adapted to close the inner ends of said discharge orifices.

4. A fuel injector comprising a body portion having a bore therein and an inlet passageway opening into said bore near one end thereof, a nozzle member removably secured to said body portion at the other end of said bore and provided with a discharge orice, a sleeve mounted' in said bore and having filtering grooves in its exterior surface, and a valve stem slidably supported in said-sleeve and extending into said nozzle for closing the discharge orice therein.

OSWALD SCHLAUPITZ.

-DI'SOLAIMER 2,067,l31.-0s`wald ,S'hlcupitz, Canton, Ohio. FUEL INJECTOR,

Patent dated January 5, 1937. Disclaimer led June 4, 1937, by the assignee; The Timken ic'ial Gazette June .'29, 1937.]

disclaims the subject matter of claims l and 4 of said Letters Patent. 

